Pump or motor



July 23, 1940. w. ERNST PUMP 0R MOTOR Filed Jan. 25, 1938 3 Sheets-Sheet 1 N RT. .o mm E VE SQN\ U W 5 mm ma m m2 N mw NN 1% l@ N* ww h* ..\|%N bv lwN A l d n -@lmm.- .mwlimimmlwwf .Q lln W mh. Nl, I I l I I I l l I I I I ww HHMIIHHHIIHHHUNM null Wr/wm i :mh /x mn/f Jn uw mm wm. ,um 1 Y VR h* ff f am f. mv erw ..v ww M. QE QN MS MM um a e h c A m .SQ S

A T TORNE Y5 July 23, 1940. ERNST 2,209,224

PUMP 0R MOTOR July 23, 1940. y w. ERNST 2,209,224

PUMP 0R MOTOR v Filed Jan. 25, 1938 3 Sheets-Sheet 5 WHL TEE 7".

ATTORNEY Patented July 23, 17940 UNITED STATES 2,209,224 PUMP on yMcvroa Walter Ernst, Mount (l'lilead,A Ohio, assigner to The Hydraulic yPress Corp. Inc., Wilmington, Del., a corporation of Delaware Application January 25, 1938, Serial No. 186,859

2 Claims.

This invention relates to hydraulic pumps or motors, and in particular, to such pumps or motors of the radial piston type.

One object of this invention is to provide a hydraulic pump or motor having radially reciprocating pistons adapted to engage a three-piece secondary rotor consisting of an annular central portion of a harder material, or with harder surface characteristics, than the side portions to l0 which it is attached and by which it is supported.

Another object is to provide a hydraulic pump or motor, asdescribed above, wherein the central annular portion of the secondary rotor is engaged by rollers supported' by needle bearings in the outer ends of pistons reciprocating radially in the radial bores of a cylinder barrel or primary rotor, supported upon a pintle.

Another object is to provide a'pump ormotor of the above described construction, wherein the side portions of the secondary rotor are rotatably supported on tapered roller bearings, cooperating with the needle bearings of the piston crossheads to counteract the outward thrust tendency imparted to the secondary rotor side members during the operation of the pump or motor.

Another object is to provide a pump or motor -of the above described construction, wherein the outer ends of the pistons are provided with squared heads having lubricant passages theref across for the more efficient distribution of lubricant, these squared heads preferably reciprocating in parallel walled guideways in the periphery of the primary rotor or cylinder barrel.

Another object is to provide a pump or motor of the above described construction, wherein the primary rotor is rotatably supported on the pintle by .means of tapered roller bearings which cooperate with the tapered roller bearings supporting the secondary rotor in such a manner as to counteract the thrusts exerted thereon during the operation of the pump or motor.

Another object is to provide a pump or moto of the above described construction, wherein opposed tapered roller bearings are employed both for supporting the primary rotor upon the pintle and the secondary rotor upon the secondary rotor support, these oppositely disposed tapered roller bearings cooperating to oppose and counteract the spreading tendency of the secondary rotor portions, thereby equalizing the internal forces and thrusts arising in, the operation of the pump or motor, reducing the deection of the axle supporting the crosshead rollers, and preventing binding both of this axle and of the crosshead 55 rollers.

(Cl. 10S-161) Another object is to provide a hydraulic pump or motor having a bell-shaped outer casing with flattened bearing portions for slidablysupporting the secondary rotor support or shiftring, and having flat wearing plates of a bearingvmetal, 5 such as bronze, to support the thrusts and|absorb the wear as the secondary rotor support moves to and fro relatively to the casing.

In the drawings:

Figure 1 is a vertical longitudinal section 10 through the hydraulic pump or motor of this invention, taken in the axis of the pintle.

Figure 2 is a vertical cross section through the axes of the radial pistons, taken along the line 2 2 in Figure 1. l5

Figure 3 is an enlarged detail view, partly in section, showing the construction of the piston and crosshead unit employed in the ,pump or motor of Figures 1 and 2.

Figure 4 is a vertical section through the piston 20 and crossheadA unit of Figure 3, taken along the broken line [-4 therein. y

Figure 5 is a top plan view of ,the piston employed in the piston and crosshead unit of Figures 3 and 4. 25

Figure 6 is a side elevation of the piston and crosshead unit of Figure 5, showing the lubricating passages.

Figure 7 is a side elevation at right angles to the side elevation of Figure .6, showing the addi- 30 tional lubricating passages therein.

In general, the pump or motor of this invention consists of a primaryr rotor, a secondary rotor adapted to rotate upon an axis eccentric to that oi the primary rotor, and pistons recipro- 35 cable in radial bores in the primary rotor, these pistons having rollers mounted in anti-friction bearings on the ends thereof and adaptedl to travel in tracks or grooves in the secondary rotor.

As the primary and secondary rotors rotate about their respective axes, the rollers on the ends oi?v the pistons travel back and forth in their tracks or grooves `in the secondary rotor, and a reciprocation is imparted to the pistons. At the same time the rollers do not need to travel back and forth in the tracks at the full operating -speed of the-pump, but merely travel fast enough to make up for the change in peripheral velocity as the primary and secondary rotors turn on their respective anti-friction bearings. At the same time the pistonexecutes a swinging movement about the anti-friction bearings supporting its crosshead rollers.

Furthermore, the secondary rotor is arranged in three portions, namely, acentral annular portion and supporting side portions secured thereto, the central annular portion having ahardened surfaceor being of harder material than the side portions, so as to resist the wear attendant upon the operation of the pump or motor, as

well as to facilitate the machining of the threey ing portions on the upper `and lower inner walls of the bell-shaped outer casing.

Referring to the drawings'in detail, Figure l shows the hydraulic pump or motor -of this in- `vention as consisting of a bell-shaped casing IIJ j having an end plate I2 secured to one end thereof, as by the cap screws I3.

The bell-shaped casing I is provided with an axial projection I4, having a longitudinal bore I5 provided with transverse bores I6 and I1 for the passage' of working fluid. Mounted in the longitudinal bore I5 is a pintle I8 having a threaded portion I9, which is engaged by a-nut 20. The nut 20 has an incision 2I formed therein, the parts 22 and 23 of the nut 20, on opposite sides thereof, being engaged by the cap screw 24 passing loosely through the'hole 25 in the part 22, and having its threads engaging the threaded lhole 26 in the part 23; By this means the nut 20 may be adl justed to the desired point, whereupon the tightening of the cap screw 24 causes the parts 22 and 23 to be forced toward one another against the threads of the threaded portion I9, thereby causing the nut 2D to remain firmly locked in position, without the danger of slippage in either direction. Y I

The purpose of this nut 20 operating upon the threaded portion I9 is for axially or longitudinally adjusting the position of the pintle I8 in order to adjust the clearances of the antifriction bearings supporting the primary rotor of the pump, as will hereinafter appear. The nut 20 and threaded portions I9 are protected by a cover cap 21 secured to the end of the projecting portion I4 of the end plate II by means of the cap screws 28, threaded into the threaded bores 29 thereof.

The pintle i8 is provided with longitudinally disposed pairs of ducts A`3l) and 3I, respectively, one pair of these ducts serving as pressure uid intake'passages and the other pair yas uid discharge passages. 'Ihe passages 30 and 3l communicate, respectively, with the cut-away portions 32 and 33 in the reduced diameter portion 34 of the pintle. `Mounted for rotation -on the reduced diameter portion 34 of the pintlel I8 is a cylinder barrel or primary rotor 35. For lthis purpose the pintle portion 34 carries the inner races 36 and 31, respectively, for Atapered roller bearings 38 and 39, the outer races 40 and `4I of which are seated in the annular recesses 42 and 43 of the primary rotor 35. The -outer races 40 are held in position by the retaining ring 44, secured by means of the set screws 45 to the threaded holes- 46 of the primary rotor or cylinder barrel 35. 'I'he outer race 4I is held in position by the forwardly'projecting flange 41 of the enlargement 48 on the inner end of the drive shaft 49, secured thereto by the set screws 50 engaging the threaded` holes 5I in. the primary x rotor 35.

The inner bearing race 31 is engaged by an end plate 52, secured to the inner end of the pintle I8 by means of the cap screws 53 secured within the threaded holes 5,4, and with a washer or a plurality of shims 55 arranged therebetween. The inner race 36, however, is loosely mounted so as to slide upon the reduced diameter portion 34 of the pintle I8,'and between it and the inwardly projecting flange 56 of the end plate II is arranged a sliding ring 51. As a consequence, it will be seen that the turning of the nut A2II upon the threaded portion I9 of the pintle I8 will cause the pintle to move axially. Assuming that this motion is to the left (Figure 1), the end plate 52 will force the inner race 31 to engage -the rollers 39.` These, in turn, engage the outer race 4I and force it and the primary rotor 35 to the left, together with the opposite outer race40 and its rollers 38. The inner race 36, however, is prevented from moving to the left because of the presence of the sliding ring 51 engaging the ilange'56 on the end plate II, and l consequently remains stationary while the pintle portion 34 slides through it. The result is thatthe diametrical clearances of the anti-friction bearings 38 and 39 are taken up in this manner so that the bearings may be kept at a tight fit ,Y

without undue binding or looseness.

. The primary rotor is provided with a bore 58 which engages the reduced diameter portion 34` ner ends with the cut-away portions 32 and 3-3' in. the pintle I 8. The cylinder barrel is also provided with lubrication passages 6I for transmitting lubricant therethrough. A similar lubricant passage 62 is provided in the drive shaft 49, the latter having an enlarged portion 63 adapted to support the inner races 64 of double tapered roller bearings 65, having an outer race 66 supported in anannular recess 61 in a projectingflange 68 in the end plate I2. The inner races 65 are held in position byy a locknut 69 having a washer 1I this being threaded upon the threaded portion 12 of the-drive shaft 49. An oil re'- taining ring 16 surrounds the drive shaft 49 in order to prevent leakage along the drive shaft.

MountedA for reciprocating in the cylinder bores 59 are pistons 9|) having flattened portions 9i upon their outer ends. Passing through the flattened` portions 9I, transversely of each piston, is a bore' 92 within which is mounted an axle 93 having reduced diameter portions 94 on its opposite ends. The axle 93 is surrounded by a dou-v scribed below. The needle bearings 95 are sep-y arated by an annular ridge 91 on 'the axle 93. The heads of the pistons 90 are .likewise flattened, as at 98, for guiding the piston heads in the primary rotor 35, in the manner hereinafter set forth. Lubricantchannels 98a and 99h are arranged 1 in a criss-cross manner in the flattened surfaces 9| and 98 (Figures 3 to 7) for distributing lubricant to the various parts.v

The crosshead rollers 96 are arranged Ato engage grooves forming trackways 99 in the secondary rotor side members |00, secured by the set screws |a to the central annular portion |0| of the secondary rotor, generally designated |02.

The central annular portion I0| is provided with an internal surface which is hardened, or of harder material than the Vside members |00 so as to withstand the thrust of the crosshead rollers, hereinafter described in detail. By this construction the three-piece secondary rotor is given the effect of a single integral secondary rotor, yet the hardened central portion |0| may be machined and hardened independently of the side portions |00. 'I'his construction likewise facilitates the assembling of the secondary rotor and enables the use of cheaper materials in the side portions |00; or of a material in the 'central annular portion |0| better adapted to give bearing support to the crosshead rollers than the material used for the side portions |00. In addition to this, the central annular portion |0| may, if desired, be made of a special bearing material, such as bronze, for additionally reducing the friction arising in the operation of the pump or motor.

The side portions |00 of the secondary rotor |02 are provided with annular shoulders |09, adapted to support the inner races |04 of antifriction tapered roller bearings |05. These inner races |04 are held in position by 'the retaining rings |01, 'secured by the set screws |09l to the side portions |00 of the secondary rotor. The tapered roller bearings |05 are supported by outer -races |06, heldin position by the retaining rings |09, secured to the secondary rotor support or shiftring ||0. The latter is provided'horizontally with diametrically opposed threaded holes I l, within which are mounted the threaded ends H2 of the shift rods H3 (Figure 2).

'I'he shiftring 0 is provided vertically with v wear platesv ||4 with attened surfaces l I5 arranged in recesses ||0 within the diametrically opposed attened portions l|1 thereof. The flattened surfaces ||5v of the wear plates ||4 are arranged to engage vthe correspondingly nattened ,j projections H0 on the interior walls of the pump casing I0. The shift rods ||9 pass outwardly through the casing I0 by way of the bores ||9. In this manner the shiftring ||0 maybe moved to and fro, and slidingly supported upon the fiattened projections I9 so as to enable it to be placed in an eccentric position relatively to the axis of the pintle I0 and cylinder barrel or primary rotor'35. When the shiftring ||0 is so placed the secondary rotor |00 revolves about an axis which is eccentric to that of the primary rotor 35 so that the pistons 90 are caused to reciprocate radially within their cylinder bores 59 by the engagement of their crosshead rollers' 96 with the grooves Aor trackways 99 'in the secondary rotor halves |00.. At the same time fluid issupplied and removed from the pump by the pintle passages 30 and' 9|, communicating with the cylinder bores 59 by way of the ports 00 and cut-away portions 92 and 39. Ports .|20 are provided at the top and-bottom of the shiftring ||0,

thereby exposing the flattened projections ||1 to the action of the oil employed as uid for the pump.

The primary rotor 35 is provided with a ridge |23 having recesses |24 immediately adjacent the tops of the cylinder bores 59, and adapted to engage the ilattened surfaces 99 of the pistons 90. In this manner the pistons 90 are provided with additional support during their reciprocation, lubricant being conducted to the opposing surfaces through the lubricating passages 98".

The operation of the pump or motor of this invention is self-evident from the foregoing description. It lwill be seen, however, that the opposing tapered roller bearings 98 and |05 cooperate to support the primary and secondary rotors' 35 and i02^in such a manner as to prevent the distortion thereof bythe thrusts arising duringoperation. In operation the thrusts of.

the pistons and their crossheads tend to cause the secondary rotor side members |00 to spread apart, but this spreading tendency is opposed and counteracted by the tapered roller bearings |05. It will be observed that the axes of these tapered roller bearings |05 intersect at the plane passing through the axes ofthe pistons 90 and cylinder bores 59.

Mounted on the drive shaft 49 (Figure l1) is a pumping gear |40 arranged between the plates |4| and |42 and meshingwith a pumping gear .|43 supported by anti-friction bearings |44 upon an axle |45. The axle |45 is mounted in sockets |46 and |41 in the plates L41 and |42, respectively. 'I'he plates |4| and |42 are separated by an annular member |48, these three members forming a casing for the pumping gears |40 and soA m and inclosing a chamber |49. Access to the chamber |49 is obtained by an aperture |50,

Vclosed by a plate |5|, secured to the plate |42 by the cap screws |52. The pumping gears and |43 together form a gear pump which is useful in connection with certain hydraulic `,machinery which the pump is adapted to operate, such as providing an auxiliary leakage pumping system for returning to the surge tank the :duid escaping past the main ram of a hydraulic press.

It will be understood that I desire to comprehend within my invention such modications as come within the scope of the claims and the invention.

Having thus fully described my invention, what I claim as new and desire to-secure by Letters Patent, is:

1. In combination in a hydraulic pump or motor, a primary rotor with cylinders, pistons reciprocable in said cylinders, a three-part secondary rotor having side parts and a central annular part, rollers on said pistons engaging said cenf tra] part, a supporting member, and tapered* roller bearings arranged between said supporting member and the side parts of said secondary rotor.

2. In combination in a hydraulic pump or mo- '4 tor, a primary rotor with cylinders, pistons reciprocable-in said cylinders, a three-part secondary rotor having side parts and a central annular part, rollers on said pistons engaging said central part, a supporting member, said side parts having axially extended portions, and tapered roller bearings arranged between said extended portions and said supporting member.

WALTER ERNST. 

